Researchers in France have developed a wall covering which blocks wi-fi signals without blocking cell phone or other radio communications.

With plans to bring a commercial product to market sometime next year, the researchers at the Grenoble Institute of Technology claim the wallpaper will be comparable in price to normal wall coverings. The wallpaper uses a coating of conductive silver crystals to block the frequency range used in wi-fi routers, keeping any wi-fi network in a covered room secure from outside connections.